Monday, November 28, 2016

The Birds and the Bees - Pollinators Matter

When we arrived in Monteverde, it was cloudy and cold. Walking through the grassy field as we approached the San Gerardo field station, my boots sunk into the mud and wet grass, and it seemed as if everything was damp. In my head, I wouldn’t imagine Monteverde as a good place to study pollination and flowering, but our schedule said otherwise. During our lecture on pollinators and pollination strategies, we learned that depending on the pollinator, plants tend to have certain floral characteristics catered toward that organism. For example, red and purple flowers were often more targeted towards plants wanting birds to pollinate them, whereas green and white flowers were more targeted at bat pollinators. Variations in smell and nectar types were other characteristics that plants altered in order to attract a certain pollinator over another. After our lecture, our professor Mau sent us into the forest with the goal to collect flowers. After about an hour of collection, we all returned to the station and began to try to separate and sort the flowers we had collected by who we thought the pollinator was.
The concept that seemed very simple in lecture seemed much more complex as I looked at the variety of flower colors, shapes, sizes and smells. Even within one color or one pollinator, there was a huge variety of flowers. After we had finished sorting, I looked at the flowers pollinated by bees, a system called “melittophily”. Flower colors ranged from purple to pink to white to yellow, and varied in size from the size of a pencil eraser to roughly the length of my hand, if not bigger. Some were very typical looking flowers, with nice landing platforms for bees and large overlapping petal, but others were tall bracts with hundreds of miniscule flowers contained within. The categories that seemed clearly defined before were less so once I actually looked at the different groups of flowers and noticed how fine the differences could be.
Another thing that really intrigued me about the flowers was how specialized and complex the relationship was between pollinators and a plant species. One of our readings discussed the concept of “floral fidelity” where a single pollinator specializes on a particular plant species. While this relationship may not be long lasting or permanent in all cases, it seems to me that these specializations could be part of why flowers are so diverse, even within a single category of pollinators, as well as across pollinators types. Despite how interesting the concept of floral fidelity is to me, the paper had grim findings in relation to pollinators. When a single species of pollinator was removed, floral fidelity of pollinators declined, in turn lowering plant reproductive success in the plant species studied, as pollinators failed to transfer pollen between the correct species. If the removal of only a single pollinator could cause this, imagining what could happen if we lose a few or even many pollinators is disheartening.  Pollinators are important in preserving our forests and environments as well our variety of fruits and vegetables, yet I feel like I see more and more reports about bee declines (only one of many groups of pollinators) extremely frequently, and little being done to try to change this.
Going to college in California, where some of the worst bee declines are occurring, brings this issue full circle for me. At Occidental College, we have tried to work against this by starting pollinator gardens, around campus, introducing feeders for some species (which comes with another set of issues) and trying to plant native plants across campus in general, rather than non natives or ornamentals. But its hard to know if this is effective, especially since Occidental is a small area within a large city- Los Angeles, and I feel like many strategies only focus on bees as pollinators, despite the variety of organisms that serve as pollinators- including butterflies, hummingbirds, flies and moths. Pollinator conservation doesn’t have to be difficult I don’t think, simply planting pollinator gardens and using fewer pesticides (if they are necessary at all, I would imagine none is even better) can make a positive impact, and since many of our fruits and vegetables (and forests) depend on it, I hope in the coming years to see a rise in efforts to conserve pollinators as well as personally help those efforts in my own life.  

Natalie Myers
Occidental College

The Silence of the Frogs


Walking through the pristine forests of Monteverde, it is easy to imagine that the forest hasn’t changed that much in the past 50, 100 or even 200 years. But that assumption would be wrong. Even though the forest is currently full of many frog calls, about 20 years ago, most of the frogs vanished leaving the forest silent.
            The two biggest schools of thought surrounding this crash, are global warming, and the chytrid. fungus. As we learned about the evidence supporting each theory, all I could think about were the dead frogs. How did over half the frog species in Monteverde disappear almost without anyone noticing. Frogs are iconic in Monteverde appearing on t-shirts, and bringing in a lot of tourist money, but most frogs have had little to no research done on their species, and many species don’t occur anywhere else in the world. While some species of frog still haven’t been seen in the 20 years since this happened in Monteverde, 75% of the most common pre-crash species have been spotted since.
            After the lecture, we walked outside to find frogs, and we didn’t have to go far. The first frog was on the plant right by the door. As we continued on our walk we saw dozens of frogs in a short period of time. My favorite species in Monteverde, the red eyed leaf frog, looks very similar to the red eyed tree frog. These little frogs spend most of their time in the canopy, so they have huge toe pads that help them climb, and they are excellent jumpers. As I was taking a picture of this frog, the flash must have caught his attention, because all of a sudden he turned to stare at me, making a great photo opportunity. This behavior is used as a defensive mechanism, with many predators being deterred when the frog opens its red eyes in the predator’s direction.
            Another thing that was evident in the forest sounds was the wide range of frog calls occurring. To my untrained ear, it sounded like there were at least 10 different species in the small area surrounding me, but as I learned each frog can make multiple different calls. There are male advertisement calls, distress calls, courtship calls, release calls and aggressive calls. This wide variety of calls could make one frog species sound like at least 5 different species of frogs. The other interesting thing about calls is how cryptic they can be. Many frogs call to let potential mates know where they are, yet after listening to a call for 10 minutes, I was still unable to spot the glass frog making the call. To avoid detection from predators, and me, frogs will infrequently make the call, or hide really well while they are making their calls.
            After a long night hike, I may not have found my glass frog, or been able to see some of the species that haven’t reappeared after the crash, but I was able to see some amazing frogs, and learn about how they are coming back, and even expanding their range to make a stronger frog population. 

Rachael Lewandowski-Sarette 
Northwestern University